Gearing.



G. G. CURTIS.

GEARING.

APPLICATION 11.31) NOV. 23, 1909.

1,?8,836 Patented N0v 18, 1913.

Mummy Attorneys.

rich.

CHARLES G. CURTIS, OF NEW YOBK, N. Y.

GEARING.

aoaassc.

Specification of Letters Patent.

Patented Nov. 18, 1913.

Application filed November 23, 1909. Serial 1Y0. 529,512.

The object of the present invention is to produce mechanical gearing fortransmitting heavy loads,larger than can be transmitted by means ofsingle gears. Oneuse of the invention is in connection with marineprmaulsi-on. particularly with turbines or high speed engines in whichthe shaft speed for economy and simplicity should be higher thanthepropeller shaft speed and in which the load to be transmitted is greaterthan can be handled by ordinary gearingQ According to the presentinvention a plurality of gears is arranged inmul-tiple upon two shaftsand the load is equalized among the various gears so that each carriesan equal or substantially equal proportion of the load, irrespective ofinequalities in the adjustment of the gears or the alinement of theteeth. In my copending application for patent, filed November 23, 1909,Serial Number I describe and illustrate several embodiments of theinvention in which an equalizing device is used for distributing theload and for allowing stress and wear to come equally on the gears In.

the present invention a difi'erent form of equalizing device is usedembodying the broad invention set forth in said co-pending application.

In the drawings: Figure 1 is a side view of a structure embodying myinvention; Fig. 2 is a vertical sectional view of the same,

the pinions being shown in elevation; and,

Fig. 3 is a diagram.

In all of the views like parts are desig-' nated by the same referencecharacters.

In the embodiment illustrated the shaft 1which is the shaft of higherspeed-carries pinions 2, 2 etc.seven being illustrated. The shaft 3,which is the shaft of lower speed, carries an equal number of gears 4,4. Either shaft 1 or 3 may be' the driving or driven shaft. As shown,the pinions' 2, 2 and gears 4, 4 are keyed or otherwise secured to theirshafts. In practice it would be diilioult, if not impossible, to soaline the gears that each will properly engage with the teeth of itsmate, and the load be properly distributed. If no provision were madefor this it is apparent that the load would be carried by one or twogears, and therefore the limit of load which could be carried would becontrolled by the breaking strain.

'of these one or two gears.

According to my invention, I provide an equaling device which permitscircumferential adj ustmcnt of the gears so that each carries its ownequal or substantially equal proportion of the load. This equalizingdevice, in the embodiment chosen for illustration, comprises an elasticsupport for the gears 4-, lon the shaft 3, suchsupport providingforcircumferential adjustment. As shown; in Fig. 1, the rim of the gear issufficientlythick to be stiff and not di-stortable under load. Thespokes 5, 5 are reduced in cross section and so shaped that when underload they will bend to a position, roughly shown in solid lines in Fig.1, thereby permitting circumferential adjustment of the rim of the gear4:. The spokes 5 should be so proportioned that th-eymay be bent to,cause. all of the teeth on the several gears a to. proportionatelyengage with the corresponding teeth on the pinions so as to carry theirdue proportion of the load, long before the elastic limit of the spokesis reached. By p p y p p rt ni s the spo es a h s can be made to carrysubstantially its proper proportion of the load.

Reference being had to Fig. 3, the tooth a. shown in solid line,represents the tooth of one of the gears 4; the tooth Z), shown indotted lines, represents the corresponding tooth of another one of thegears 4. The teeth a and I) are intended to represent the extremepositions of teeth due to the maximum error of alinement. This appliesto where the two gears l, 4; are used, or more.

0 represents thecenter of the gear 4:, the angle X Y 0 representing thecircumferential extent of maximum error.

If 62 represents the position of all teeth when under load, the angleXcZ will represent the extent of maximum circumferential displacement ofthe gears, and the angle Y 0 Z, the angle of minimum displacement. If weasume that the angle X In is onetenth of the angle X 0 Z and that tengears are used, it is apparent that the distribution of load will bewithin ten per cent. To state the matter in another way,'the gear 6,

when moved to the position (Z, will carry with any number of gears andfore the limit of; elasticity of the stroke is reached must be very muchgreater,as, for

instance, the positionc e.

7 From the foregoing description it will be seen thataltho'ugh the teethon the gears cannot be so adjusted that when at rest they will equallyintermeshit is apparent that, when the working load is upon the twoshafts, the gears Will circu'mfercnt-ially adjust themselves so thatthe-load will be substantially equally distributed among the differentgears. Theidea may cs-carried out it is apparent that theequalizingdevice may be applied to all 01 part of the gears, 'and'thatwhen applied wholly'to the ears on'one shaft, the gears on the other'sha t, such as the pinions 2, need not be separategzand-it is alsoa'pparent that bevel or spiral gears may-be used. (It is also apparentthat anyv other form of an elastic or flexible equalizing device maybe,used,'the elastic spokes being chosen simply for the purpose ofillustrating the preferred embodiment of the 'invention.

In accordance with the provisions of. the

patent statutes, I have described the'principle of my invention,together with the afiparatus which I now consider to represent the bestembodiment thereof; but I desire to have it understood that theapparatus shown is merely illustrative and that the invention can becarried out in other ways.

Having now described my invention, what meshing tooth gears, asufficient I claim as new and desire to secure by Let ters Patent, is

1. In a" gearing for transmitting heavy loads, the combination with twoshafts, 0f

several pairs of intermeshing tooth gears mounted on such shafts andtransmitting motion from one shaft to the other, there be ing embodiedin the construction unchecked elastic means permitting the'relative crcumferential self-ad ustment of the several pairs of gears todistribute the load and having suflicient strength to carry the load,substantially as set forth.

2. In a gearing for transmitting heavy loads, the combination of anumber of intermeshing tooth gears, the teeth of which are supported by'elastic means yielding in the directionof the stress, substantially asset forth. i

3. In a, gearing for transmitting heavy loads, the combination of anumber of internumber of such gears having yielding elastic spokes todistribute the load, substantially as set forth. a 4. In a earing fortransmitting heavy loadsand or reducing speed, the combina- 'tion ofanumber of. driving pnnons and driven gear wheels, said driven gearwheels being provided with yielding elastic spokes to dlstribute theload, substantially as set forth. y

This specification signed and witnessed this 22nd day-of Nov., 190$).

CHARLES G. CURTIS.

- Witnesses:

LEONARD H. DYEEY, JO N L. Lo'rsoit.

Copies of this patent may be obtained for Patents,

Washington, D. G.

